Astros starter Roy Oswalt did not come out to pitch the fifth inning Sunday against the Pirates at PNC Park because of a left ankle contusion he suffered in the second inning.
Pedro Alvarez ripped a liner that one-hopped off Oswalt's lower left leg for a single. Trainers came out to check on Oswalt, who remained in the game.
Oswalt was less effective after the incident, and did not come out to pitch the fifth inning. There's no official word yet regarding how much time Oswalt will miss.
This season, Oswalt has a 3.08 through 120 innings for an Astros team that is trying to avoid the NL Central cellar.